Spark-plug short-circuiting device



June 26, 1 928.

M. J. GEBHARDT SPARK PLUG SHORT- CIRCUITING DEVICE Filed Oct. '7, 1926 Mr a n W a J Patented June 26, 1928 UNITED STATES 7 MICHAEL J. GEBHARDT, 0F HOWARD LAKE, MINNESOTA.

SPARK-PLUG SHORT-GIRGUITING DEVICE.

Application med October 7, 1926. Serial No. 140,201.

This invention relates to spark plug short circuiting devices and more particularly to a device of this character adapted to be supported by the spark plug.

An important object of the invention is to provide a device of this character which is operable from the dash of the vehicle, so that a test of the engine may be made Without the operator leaving the vehicle.

A further object of the invention is to produce a device of this character which may be very readily and cheaply produced, which may be readily applied to thespark plug and which may be readily transferred from one spark plug to another when the spark plugs are changed.

These and other objects I attain by the construction shown in the accompanying drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a side elevation I showing a spark plug short-circuiting device constructed in accordance with my invention and applied to an engine;

Figure 2 is a plan view of a single unit;

Figure 3 is a detail enlarged side elevation partially broken away showing the construc- .tion of the short-circuiting unit proper;

Figure 4: is a detail sectional view through the dash control element.

Referring now more particularly to the drawing, the numeral 10 generally designates an internal combustion engine having a plurality of spark plugs 11. In accordance with my invention, I provide each spark plug with a fiber plate 12 which is secured to the spark plug by passing the upper end of the central electrode 13 of'the spark plug through an opening formed in the plate and then placing a nut 14 upon the upper end of the spark plug. Pivoted upon the plate at 15 is a lever 16, one end of which may be swung to engage with the upper "end of the electrode 13 or the attached nut 14. The opposite end of the lever 16 has means 17 for securing thereto one end of a Bowden wire 18. The end of the plate 12 remote from the spark plug 13 is provided with a. split clamp 19, the sections of which may be forced together by the securing elements 20 to secure, by said clamp, one end of a hous ing 21 for the Bo-wden wire 18.

The numeral 22 indicates a support arranged adjacent the drivers seat of the vehicle and electrically connected with the frame of the Vehicle, as generally indicated at 23. This support, which preferably comprises the instrument board of the vehicle, has mounted therein tubes 24 corresponding in number and arrangement to the spark plugs 11. These tubes each have a flanged head 25 abutting the rear face of the instrument board and having its rear end threaded for the passage of a clamping nut 26. En-

gaged with .the rear extremities of the tubes 24 are couplings 27 by means of which the free ends of the housings 21 are. connected therewith. Slidable in each tube 24 is a plunger 28, the inner end of which is. connected to the Bowden wire 18 which is directed through the associated housing 21' and the outer end of which has a head 29 by means of which it may be engaged. It will. be obvious that by pulling out on the head 29 of a plunger 28, the associated lever 16 will beswung about its pivot 15 and electrically connected with the spark plug to which its mounting plate 12 is attached. Current, instead of passing to the plug, will pass through the lever 16, wire 18 and either the housing 21 or the plunger28 to the tube 24.- and thus to the support 22 and the ground. By this means, the successive cylinders can be cut out to determine which cylinder is missing.

Sincefthe construction hereinbef-ore set forth is capable of a certain range of change and modification without materially departing from thespirit of the invention, I do not limit myself to such specific structure ex cept as hereinafter claimed.

I claim v A spark plug short circuiting device comprising aplate of insulating material provided at one end with an opening adapted to receive a terminal, clamp members mounted at the opposite end of the plate, a lever of conducting material pivoted at a point between its ends to the plate at a point between the said opening and the clamp members, said lever having one end portion of suflicient length to pass over the opening and the other end of such length that it is spaced from the clamp members when the firstmentioned end is toward the opening, and a wire connected atone end with the shorter end of the lever and trained between the clamp members.

In testimony whereof I hereunto aflix my signature.

MICHAEL J. GEBHARDT. 

